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26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B

作者： Bernier, J.S. Weir, W.C.S. Fontecchio, M. Sisson Jr., R.D. Bose, S. Materials Science and Eng. Program Mechanical Engineering Dept Worcester Polytechnic Institute Worcester MA 01609 United States Materials and Processing Engineering Pratt and Whitney East Hartford CT 06108 United States

The coating thickness profiles for EB-PVD TBCs deposited on stationary cylinders have been experimentally measured and theoretically modeled using Knudsen's cosine law of emissions {1}. A comparison of the experimental results with the model reveals that the model needs to be modified to account for the sticking coefficient as well as a ricochet factor. These results are also discussed in terms of the effects of substrate temperature on the sticking coefficient, the ricochet factor, and coating density.

关键词： Thermal insulating materials

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Microstructural evolution of EB-PVD TBC's on cylinderical surfaces

Microstructural evolution of EB-PVD TBC's on cylinderical su...

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26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B

作者： Bernier, J. Maniruzzaman, Md. Fontecchio, M. Sisson Jr., R.D. Bose, S. Materials Science and Eng. Program Mechanical Engineering Dept Worcester Polytechnic Institute Worcester MA 01609 United States Materials and Processing Engineering Pratt and Whitney East Hartford CT 06108 United States

The microstructures of EB-PVD TBC's have been characterized as a function of angular position and cylinder height on stationary cylindrical surfaces in the coating chamber. The microstructures were evaluated using x-ray diffraction for qualitative crystallographic texture as well as by optical microscopy and scanning electron microscopy for crystal column growth morphology. The results revealed several very strong crystallographic textures as well as a variety of crystal growth morphology.

关键词： Thermal insulating materials

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Building bridges to material properties in general chemistry laboratories: A model for integration across disciplines

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Journal of Engineering Education 2002年第4期91卷 379-386页

作者： Demetry, Chrysanthe Gurland, Suzanne T. Kildahl, Nicholas Department of Mechanical Engineering Mat. Science and Engineering Program Worcester Polytechnic Institute Frances L. Hiatt Sch. of Psychology Clark University Department of Chemistry Worcester Polytechnic Institute Worcester Polytechnic Institute Mechanical Engineering Department 100 Institute Road Worcester MA 01609 Clark University Department of Psychology 950 Main Street Worcester MA 01610 Worcester Polytechnic Institute Department of Chemistry 100 Institute Road Worcester MA 01609

Many engineering students enter and exit general chemistry courses with little appreciation of chemistry's relevance to other fields. At WPI many of these students go on to take introductory materials science and arrive with poor attitudes about chemistry and little retention of key concepts, but then become more engaged as they discover connections to engineering applications. Consequently, instructors in chemistry and mechanical engineering collaborated to augment general chemistry laboratories with explicit "bridges" to material properties and applications. Evaluation results showed that while students' attitudes toward chemistry were unaffected by bridging, particular aspects of the students' lab experience were enhanced to a statistically significant degree. Similar cross-disciplinary collaborations might be considered elsewhere as a means of helping students find meaning and integrate subject matter, in a manner that is more feasible than large-scale course or curriculum restructuring.

关键词： Engineering education

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A New Quenching Characterization System for Steels

A New Quenching Characterization System for Steels

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Heat Treating: Proceedings of the 21st Conference

作者： Chaves, Juan C. Maniruzzaman, Mohammed Sisson Jr., Richard D. Mat. Science and Engineering Program Center for Heat Treating Excellence Worcester Polytechnic Institute Worcester MA 01609

A new quenching characterization measurement system has been developed to experimentally determine the temperature versus time data for selected steel alloys in mineral and vegetable oils. The main features of the quenching characterization system are the data acquisition system, the data analysis hardware and software and the probe. The probe can be fabricated from the specific alloy being considered. The steel probe allows the characterization of the steel-quenchant system. The analysis of the quenching data can provide cooling rates as well as heat transfer coefficients that may be used for further analysis of a quenched component. The results and analysis of data from AISI 4140 quenched in mineral oils are presented and discussed.

关键词： Quenching

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Application of high temperature superconducting wire to magnetostrictive transducers for underwater sonar

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NAVAL ENGINEERS JOURNAL 1997年第1期109卷 31-39页

作者： Joshi, CH Lindberg, JF Clark, AE Dr. Chad H. Joshi:is president of Energen Incorporated an engineering and development firm specializing in cryogenic and electromechanical systems. The research presented here was conducted while he was employed at American Superconductor Coporation where he held both technical and program management positions. While there Dr. Joshi managed the development of several demonstration products including the sonar transducer presented here. He holds M.S. and Sc.D. degreesfrom the Massachusetts Institute of Technology and a B.S. degree from the Worcester Polytechnic Institute. He has worked in several diverse fields including solar energy fluidized bed technology and superconductivity. His work on stochastic analysis of solar insolation was recognized by the ASME and his doctoral research was accorded international recognition for its unique contribution to understanding quenching in superconducting magnets. Dr. Joshi has numerous patents and more than thirty-five technical publications to his credit. He is a registered Professional Engineer in Massachusetts and an active member of ASME and IEEE. He is a co-founder and treasurer of the New England Chapter of the Cryogenics Society of America. He will be listed in Whos Who in the East in 1997. Jan Lindberg:is a physicist in the Transducers and Arrays Division of the Naval Undersea Warfare Center in New London Connecticut. He leads NUWC'S exploratory development efforts for transduction science and currently is spearheading an effort to introduce high-energy density active materials into tactical sonar systems. With the discovery of high temperature superconductivity he saw the potential benefit of integrating several emerging technologies and enticed American Superconductor Corp. to develop a high temperature superconducting transducer which resulted in the March 1993 demonstration of the world's first integrated high temperature superconducting device. Mr. Lindberg's current interests involve design of high power ultrasonic copolymer arrays characterization of

A low-frequency underwater acoustic transducer integrating high-temperature superconducting (HTS) coils and terbium-dysprosium (TbDy) magnetostrictive material was designed, fabricated and tested. This represents a novel application for high-temperature superconductivity and is a first example of an integrated system involving HTS coils cooled by a mechanical cryocooler. It also brings HTS technology together with a novel magnetic materials technology. The I-ITS coils were fabricated using react-and-wind BiSrCaCuO-2223 HTS wires. They produce a peak field of 0.1 Tesla at 50 K. A single-stage, Stirling-cycle cryocooler was used to cool the coils and the TbDy driver to cryogenic temperatures (50-65K). The coils provide an AC magnetic field superimposed on a DC bias field, which produces oscillatory strain within the magnetostrictive rod;this motion is transmitted through a cryostat to two head masses which project sound into the surrounding environment. High power acoustic output can be obtained by operating the transducer at its resonance frequencies of 520 Hz in air and 430 Hz underwater. This development demonstrates that, unlike low temperature superconductors, HTS wires can be considered for AC applications due to the low losses in these superconductors and the higher heat capacities of materials at temperatures above liquid helium.

关键词： Underwater equipment

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Influence of human engineering on manning levels and human performance on ships

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NAVAL ENGINEERS JOURNAL 1997年第5期109卷 67-76页

作者： Anderson, DE Oberman, FR Malone, TB Baker, CC David E. Anderson:has a bachelor of science degree in environmental engineering from Florida Technological University and a master's degree in environmental engineering from the University of Central Florida. He is a graduate of the Naval Sea Systems Command's Engineer-In-Training (EIT) Program. Mr. Anderson was instrumental in introducing the collective protection system (CPS) in the U.S. Navy developing the initial forward-fit package for the USS Gunston Hall and the engineering change proposal (ECP) for the USS Wasp. In 1990 he joined the Human Systems Integration (HSI) Division (SEA 55W5) where he was task leader for auxiliary ships. He is currently the HSI manager for the future technology variant of the SeaLift ship and the future carrier. Association of Scientists and Engineers 33rdAnnual Technical Symposium 26 April 1996. Fred R. Oberman:has B.A. and M.A. degrees from the University of Chicago and Loyola University (experimental psychology) and an M.S. degree in industrial engineering and operations research from Virginia Polytechnic Institute (VPI). He has more than 30 years experience in HSI management planning research analysis design and testing in government and private sector positions. He is currently responsible for NavSea HSI generic research and tool development efforts. He is responsible for Human Engineering Specifications and Standards (Commercial Hypertext) and is the NavSea 03D7 representative on HSI in Performance Specifications and for integration of HSI within Integrated Logistic Support (ILS). He has served as DoD HSI SubTAG chair and member of the Simulation and Modeling Test and Evaluation Display and Control Systems Human Computer Interaction Specifications and Standards and Systems Design Sub Tags as a member of the Society of Naval Architects and Marine Engineers (SNAME) Systems Safety Panel and a member of NATO RSG 14 on man-machine analysis. Thomas B. Malone: CHFEP received a Ph.D. in experimental psychology from Fordham University in 1964. He is president of Carlow

The objectives of Human Engineering (HE) are generally viewed as increasing human performance, reducing human error, enhancing personnel and equipment safety, and reducing training and related personnel costs. There are other benefits that are thoroughly consistent with the direction of the Navy of the future, chief among these is reduction of required numbers of personnel to operate and maintain Navy ships. The Naval Research Advisory Committee (NRAC) report on Man-Machine Technology in the Navy estimated that one of the benefits from increased application of man-machine technology to Navy ship design is personnel reduction as well as improving system availability, effectiveness, and safety The objective of this paper is to discuss aspects of the human engineering design of ships and systems that affect manning requirements, and impact human-performance and safety The paper will also discuss how the application of human engineering leads to improved performance, and crew safety, and reduced workload, all of which influence manning levels. Finally, the paper presents a discussion of tools and case studies of good human engineering design practices which reduce manning.

关键词： Human engineering

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A direct algorithm for computing the transitive closure of a two-dimensionally structured file 3rd

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3rd Symposium on Mathematical Fundamentals of database and Knowledge Base Systems, MFDBS 1991

作者： Taylor, Stephen Hachem, Nabil I. Data General Corporation WestboroMA01531 United States Data/Knowledge Base Research Group Computer Science Department Worcester Polytechnic Institute WorcesterMA01609 United States

ISBN: (纸本)9783540540090

It is well-known that the computation cost to find the transitive closure (TC) of a graph stored as an adjacency matrix is the same, to within a constant factor, as matrix multiplication. In this paper, we present a new TC algorithm based on double hashing and two-dimensionally organized files. We show that, when using this algorithm, the computation and i/o costs of finding the TC of a database relation is like that of performing a relational composition operation. For sparse closures, sparse compositions will be performed, which may be significantly more thrifty than the corresponding matrix operations, which must be at least O(n2), and for which most algorithms are O(n3). © Springer-Verlag Berlin Heidelberg 1991.

关键词： Matrix algebra

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A COMPUTER-MODEL FOR SHIPBOARD ENERGY ANALYSIS

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NAVAL ENGINEERS JOURNAL 1984年第5期96卷 33-45页

作者： DETOLLA, JP FLEMING, JR Joseph DeTolla:is a ship systems engineer in the Ship Systems Engineering Division SEA 56D5 at the Naval Sea Systems Command. His career with the Navy started in 1965 at the Philadelphia Naval Shipyard Design Division. In 1971 he transferred to the Naval Ship Engineering Center. He has held positions as a fluid systems design engineer and auxiliary systems design integration engineer. Mr. DeTolla has worked extensively in the synthesis and analysis of total energy systems notably the design development of the FFG-7 class waste heat recovery system. He is NA VSEA's machinery group computer supported design project coordinator and is managing the development of a machinery systems data base load forecasting algorithms and design analysis computer programs. Mr. DeTolla has a bachelor of science degree in mechanical engineering from Drexel University and a master of engineering administration degree from George Washington University. He is a registered professional engineer in the District of Columbia and has written several technical papers on waste heat recovery and energy conservation. Jeffrey Fleming:is a senior project engineer in the Energy R&D Office at the David Taylor Naval Ship R&D Center. In his current position as group leader for the future fleet energy conservation portion of the Navy's energy R&D program he is responsible for the identification and development of advanced components and subsystems which will lead to reductions in the fossil fuel consumption of future ships. Over the past several years he has also directed the development and application of total energy computer analysis techniques for the assessment of conventional and advanced shipboard machinery concepts. Mr. Fleming is a 1971 graduate electrical engineer of Virginia Polytechnic Institute and received his MS in electrical engineering from Johns Hopkins University in 1975. Mr. Fleming has authored various technical publications and was the recipient of the Severn Technical Society's “Best Technical Paper of the Year” award in 1

In support of the Navy's efforts to improve the energy usage of future ships and thereby to reduce fleet operating costs, a large scale computer model has been developed by the David Taylor Naval Ship Research and Development Center (DTNSRDC) to analyze the performance of shipboard energy systems for applications other than nuclear or oil-fired steam propulsion plants. This paper discusses the applications and utility of this computer program as a performance analysis tool for design of ship machinery systems. The program is a simulation model that performs a complete thermodynamic analysis of a user-specified energy system. It offers considerable flexibility in analyzing a variety of propulsion, electrical, and auxiliary plant configurations through a component building block structure. Component subroutines that model the performance of shipboard equipment such as engines, boilers, generators, and compressors are available from the program library. Component subroutines are selected and linked in the program to model the desired machinery plant functional configurations. The operation of the defined shipboard energy system may then be simulated over a user-specified scenario of temperature, time, and load profiles. The program output furnishes information on component operating characteristics and fuel demands, which allows evaluation of the total system performance.

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RUDDER ROLL STABILIZATION FOR COAST GUARD CUTTERS AND FRIGATES

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NAVAL ENGINEERS JOURNAL 1983年第3期95卷 267-282页

作者： BAITIS, E WOOLAVER, DA BECK, TA Dr. Erich Baitis: a native of Germany came to the David W. Taylor Naval Ship Research and Development Center in 1957 as a co-operative student/trainee and received his Bachelor of Science Degree in Physics from Virginia Polytechnic Institute. As a 32-year-old naval architect in 1971 he received both the VietnamHonorServiceMedaland the Navy'sMeritoriousCivilianServiceAwardfor his eight months as liaison with the Vietnamese NAVVS ferro-cement ship program. As head of the Seakeeping and Stabilization Group of the Surface Ship Dynamics Branch his work has led to the development of a new standard Ship Motion Computer Program and the application of ship motions to ship habitability operability and survivability problems. A major area of this work has been the ship/aircraft interface which is particularly sensitive to ship motions wind and other environmental factors. Mr. Dennis A. Woolaver:has been employed as a Naval Architect at the David W. Taylor Naval Ship Research and Development Center since 1965 where his work has resulted in numerous patents. He received his Bachelor of Science Degree in Electrical Engineering from George Washington University where he also completed graduate work in Communication Theory. Additional fields of study include Computer Science and Personnel Management. Current efforts are directed toward surface ship motion mitigation data acquisition and statistical analysis. He is a member of the Society of Naval Architects and Marine Engineers. Lt. Tom A. Beck USCG: joined the UnitedStatesCoastGuardin 1966 where he trained as an Electronics Technician. He received a Bachelor of Science Degree in Electrical Engineering from Columbia University in 1978. From 1978 to 1979 he was an Electronics Project Officer at the CoastGuardElectronics Laboratory in Alexandria Virginia. Since 1980 he has been a Research and Development Project Officer in the Sensor Technology Branch of the CoastGuardsOffice of Research and Development. Lt. Beck is a member of the Institute of Electronic and Elect

The potential use of rudders as anti-roll devices has long been recognized. However, the possible interference of this secondary function of the rudder with its primary role as the steering mechanism has prevented, for many years, the development of practical rudder roll stabilizers. The practical feasibility of rudder roll stabilization has, however, in recent years been demonstrated by two systems designed and developed for operational evaluation aboard two different U.S. C oast G uard Cutters, i.e., Jarvis and Mellon of the 3,000-ton, 378-foot HAMILTON Class. The authors describe the major components of the rudder roll stabilization (RRS) system, along with the design goals and methodology as applied to these first two prototypes. In addition, a brief history of the hardware development is provided in order to show some of the lessons learned. The near flawless performance of the prototypes over the past four years of operational use in the North Pacific is documented. Results from various sea trials and reports of the ship operators are cited and discussed. The paper concludes with a discussion of the costs and benefits of roll stabilization achieved using both a modern anti-roll fin system, as well as two different performance level RRS systems. The benefits of roll stabilization are demonstrated by the relative expansion in the operational envelopes of the USS OLIVER HAZARD PERRY (FFG-7) Class. The varying levels of roll stabilization suggest that the merits of fins and RRS systems are strongly dependent on mission requirements and the environment. The demonstrated performance of the reliable RRS system offers the naval ship acquisition manager a good economical stabilization system.

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Computer science and engineering education: Current trends, new dimensions and related professional programs 78

Computer science and engineering education: Current trends, ...

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9th SIGCSE Technical Symposium on Computer science Education, SIGCSE 1978

作者： Jehn, Lawrence A. Rine, David C. Sondak, Norman Computer Science Dept. University of Dayton DaytonOH United States Information Science Program Western Illinois University MacombIL United States Computer Science Dept. Worcester Polytechnic Institute WorcesterMA United States

ISBN: (纸本)9781450374347

The role of the computer in engineering practice is ever increasing. The computer performs such tasks as: simple calculations;on line data recording and synthesis;acting as a control unit providing feedback;statistical analysis of large data sets;information retrieval and storage;and the simulation of large complex systems. © 1978 Association for Computing Machinery Inc. All rights reserved.

关键词： Computer control systems

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